Participating Hospitals:

  • Banner Casa Grande Medical Center
  • Chandler Regional Medical Center
  • Mercy Gilbert Medical Center


Dr. John R. Tretter is a cardiologist board certified in Cardiovascular Medicine and Internal Medicine. Dr. Tretter received his medical degree from Autonomous University of Guadalajara, Guadalajara, México. He completed his internal medicine residency at Harbor Hospital, Baltimore, Maryland in 1989 and completed his cardiology fellowship at the Mount Sinai Medical Center in Cleveland, Ohio. Dr. Tretter is a member of the American College of Cardiology and the American Society of Echocardiography. He practiced with the Slocum-Dickson Medical group in upstate New York for nearly 20 years. He is bilingual in English and Spanish.

Dr. Tretter enjoys spending time with his family and the great outdoors. In 2009 he traded snowboarding on the slopes of upstate New York for mountain biking in the beautiful Arizona desert terrain to join Premier Cardiovascular Center (PCC). He has extensive experience in various cardiovascular diseases and provides services at our Casa Grande location, Chandler Regional Medical Center and Banner Casa Grande Medical Center, where he served as the Chief of Cardiology.

In addition to non invasive cardiology, Dr. Tretter also performs in-office Radiofrequency Vein Ablations to treat varicose veins, venous reflux and venous insufficiency.